Research has consistently shown that heavy alcohol use during the first year of college is linked to current and future life problems. Thus, alcohol misuse among college students is a major public health concern. Disinhibited personality, stress, and negative affect are associated with high levels of alcohol use in college students. The relations between these variables have been partly explained by the self-medication model. It is likely that disinhibited personality plays a critical role in self-medication model of alcohol use through exposure (mediation) and reactivity (moderation) processes. Thus, I proposed to examine the self- medication model of alcohol use by considering mediational and moderational processes of personality, namely impulsivity, using a longitudinal data set of college freshmen. The specific aims of the current proposal are: 1) examine the relation between negative affect and alcohol use among college students with impulsivity and gender as moderators, 2) examine the relation between stress and alcohol use among college students with impulsivity as a moderator, 3) examine the relation between stress and negative affect among college students with gender as a moderator, and 4) examine the combination ofexposure-reactivity model of impulsivity with the self-medication model of alcohol use among college students.